Refractory Carbide Coatings With Additive Gradient Sintering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing refractory metal carbide coatings face challenges in achieving high mechanical stability, flexibility in geometry, and safety due to the use of toxic sintering additives like cobalt, which are costly and pose health and environmental risks, especially in high-temperature applications such as semiconductor crystal growth.
Innovation Solution
A method involving two aqueous suspensions, one with a higher concentration of sintering additives and one with a lower or no additives, applied to a substrate and sintered together, forming a layered structure with a density gradient, using safer and more effective refractory metal silicides, nitrides, and borides to enhance compaction and protect against corrosive media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a polyolefin resin coating layer is formed on a polyolefin substrate using conventional methods, then the coating can be applied, but the coating layer becomes uneven and contains resin aggregates due to poor wetting and high viscosity
Solution Approach 1:
The patent changes the molecular weight distribution parameters of the polyolefin resin by using resin with a specific weight average molecular weight (Mw) of 10,000 to 1,000,000 and a polydispersity index (PDI) of 1.05 or less. This parameter optimization ensures uniform coating by controlling resin viscosity and wetting characteristics, eliminating aggregates while maintaining coating integrity.
Solution Approach 2:
The patent replaces conventional mechanical coating methods with a solution-based coating approach where the resin is dissolved in a solvent to form a uniform coating solution. This substitution allows for more controlled resin deposition and eliminates the mechanical aggregation issues that occur with direct resin application.
2Reliability
If conventional polyolefin resin is used for coating, then the coating can be formed, but the coating layer has poor adhesion and contains aggregates
Solution Approach 1:
The patent optimizes the molecular weight parameters of the polyolefin resin, specifically setting the weight average molecular weight (Mw) between 10,000 and 1,000,000 and the polydispersity index (PDI) at 1.05 or less. These parameter changes improve both adhesion and uniformity by controlling resin chain length and distribution, ensuring proper wetting and bonding to the substrate.
Solution Approach 2:
The patent creates a composite coating system by combining polyolefin resin with specific molecular weight characteristics and controlling the polydispersity index. This composite approach ensures that the resin molecules are uniformly distributed and properly bonded to the substrate, eliminating aggregates while maintaining strong adhesion.
3Strength
If high molecular weight polyolefin resin is used, then the coating has good film formation, but the resin viscosity is too high for uniform coating
Solution Approach 1:
The patent precisely controls the molecular weight parameters by setting the weight average molecular weight (Mw) between 10,000 and 1,000,000 and the polydispersity index (PDI) at 1.05 or less. This parameter optimization balances film formation capability with coating applicability, ensuring the resin is viscous enough to form an intact film but not so viscous that it creates aggregates or poor wetting.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method produces coatings with improved mechanical stability, reduced susceptibility to cracking, increased flexibility in geometry, and safety by avoiding toxic additives, enhancing protection in high-temperature applications with a higher evaporation rate and growth rate.
Implementation Method 1
a coating solution is applied to a substrate and dried
Implementation Method 2
the coated layer is heated to melt and level the resin
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a method for producing coated substrates, wherein a first aqueous suspension and a second aqueous suspension are produced, at least one layer of the first aqueous suspension is applied onto a substrate, at least one layer of the second aqueous suspension is applied onto the at least one layer of the first aqueous suspension applied onto the substrate, and the substrate coated in this manner is subjected to a sintering process. The first aqueous suspension contains at least one refractory metal carbide, at least one sinter additive selected from the group consisting of refractory metal silicides, refractory metal nitrides, refractory metal borides, silicon, silicon carbide, boron nitride, tungsten carbide, vanadium carbide, molybdenum carbide, boron carbide, and mixtures thereof, and water or consists thereof. The second aqueous suspension likewise contains at least one refractory metal carbide and water. Additionally, the second aqueous suspension can contain at least one sinter additive selected from the group consisting of refractory metal silicides, refractory metal nitrides, refractory metal borides, silicon, silicon carbide, boron nitride, tungsten carbide, vanadium carbide, molybdenum carbide, boron carbide, and mixtures thereof, wherein the content by weight percentage of the at least one sinter additive in the second aqueous suspension, based on the total weight of the second aqueous suspension, is less than the content by weight percentage of the at least one sinter additive in the first aqueous suspension, based on the total weight of the first aqueous suspension. Alternatively, the second aqueous suspension can contain no additives. The invention additionally relates to a coated substrate which is produced or can be produced using the method according to the invention and to the use of such a coated substrate.